Road maps

A road map is one of the most widely used map types.

• These maps show major and minor highways and roads (depending on detail)

• as well as things like airports, city locations and points of interest like parks, campgrounds and monuments.

• Major highways on a road map are generally red and larger than other roads,

• while minor roads are a lighter color and a narrower line.

Road maps

Library ggmap

library(ggmap)

qmap("Mannheim")

MA_map <- qmap("Mannheim",zoom=14)

• We load a library with library()

Other zoom level

qmap(location = 'Mannheim', zoom = 12)

Get closer

qmap(location = 'Mannheim', zoom = 13)

Get very close

qmap(location = 'Mannheim', zoom = 20)

ggmap - source

qmap(location = 'Mannheim', zoom = 14, source="osm")

ggmap - maptype

qmap(location = 'Mannheim', zoom = 14, maptype="satellite")

ggmap - maptype

qmap(location = 'Mannheim', zoom = 14, maptype="hybrid")

ggmap - maptype

qmap(location = 'Mannheim', zoom = 14,
 maptype="toner",source="stamen")

ggmap - create an object

MA_map <- qmap(location = 'Mannheim', zoom = 14,
 maptype="toner",source="stamen")

Geocoding

Geocoding (…) uses a description of a location, most typically a postal address or place name, to find geographic coordinates from spatial reference data …

Wikipedia - Geocoding

geocode("Mannheim Wasserturm",source="google")

Get the distance between 2 points

mapdist("Q1, 4 Mannheim","B2, 1 Mannheim")

##             from             to   m    km     miles seconds  minutes
## 1 Q1, 4 Mannheim B2, 1 Mannheim 746 0.746 0.4635644     211 3.516667
##        hours
## 1 0.05861111

mapdist("Q1, 4 Mannheim","B2, 1 Mannheim",mode="walking")

##             from             to   m    km     miles seconds minutes
## 1 Q1, 4 Mannheim B2, 1 Mannheim 546 0.546 0.3392844     420       7
##       hours
## 1 0.1166667

Get another distance

mapdist("Q1, 4 Mannheim","B2, 1 Mannheim",mode="bicycling")

##             from             to   m    km    miles seconds  minutes
## 1 Q1, 4 Mannheim B2, 1 Mannheim 555 0.555 0.344877     215 3.583333
##        hours
## 1 0.05972222

Geocoding - points of interest

POI1 <- geocode("B2, 1 Mannheim",source="google")
POI2 <- geocode("Hbf Mannheim",source="google")
POI3 <- geocode("Wasserturm Mannheim",source="google")
ListPOI <-rbind(POI1,POI2,POI3)
POI1;POI2;POI3

##        lon      lat
## 1 8.462844 49.48569

##        lon      lat
## 1 8.469879 49.47972

##        lon      lat
## 1 8.473664 49.48483

Points in map

MA_map +
geom_point(aes(x = lon, y = lat),
data = ListPOI)

Points in map

MA_map +
geom_point(aes(x = lon, y = lat),col="red",
data = ListPOI)

ggmap - adding different colors

ListPOI$color <- c("A","B","C")
MA_map +
geom_point(aes(x = lon, y = lat,col=color),
data = ListPOI)

ggmap - bigger dots

ListPOI$size <- c(10,20,30)
MA_map +
geom_point(aes(x = lon, y = lat,col=color,size=size),
data = ListPOI)

Resources

• Article by David Kahle and Hadley Wickham on the usage of ggmap.

More about adding points

• Usage of geom_point
• Question on stackoverflow

Cheatsheet

• Cheatsheet on data visualisation

Resources and literature

ggmap: Spatial Visualization with ggplot2

by David Kahle and Hadley Wickham